Mixing drum for mixing concrete, mortar, and the like



H. RUEF .July 1930.-

MIXING DRUM FOR MIXING CONCRETE, MORTAR, AND THE LIKE Filed March 1, 1928 2 Sheets-Sheet 1 July 15, 1930.

I H. RUEF MIXING DRUM FOR MIXING CONCRETE, MORTAR- AND THE 'LIKE Filed March 1, 1928 2 Sheets-Sheet 2 jilrenzor Patented July 15, 1936 rec HEINRICH RITEF, OF ZURICH, SWITZERLAND MIXING DRUM FOB- IVIIXING CONCRETE, MORTAR, AND THE LIKE Application filed March 1, 1928, Serial No. 258,370, and in Switzerland March 5, 1927.

In mixing concrete, mortar and the like, efiective alternate movements of the materials to be mixed in the axial direction of the mixing drum and in the circumferential direction of the latter while compelling the material to constantly change its position in the drum are the principal condition in order to produce a homogenous mixture. Inclined plates symmetrically arranged within the drum and which cause the materials to be mixed and fed towards these plates by lifting blades to bound, by opposite axial movements, against each other prevent such an alternate movement. Further lifting blades on the drum acting in axially opposite directions work insufficiently as the mixing is not a positive action but is to a very large degree accidental.

In order to obtain an intimate mixing in a short time with the method according to the present invention the material to be mixed which is lifted in a rotating mixing drum is conducted in such a manner and with free fall in the interior of the drum over guide blades that besides a spreading of the material on the circumference of the drum, forms streams of material which flow in the axial direction of the drum to pass each other.

This method will now be explained with 39 reference to the accompanying drawings, on which several constructional examples of mixing drums for carrying into effect that method, and which drums also form subject matter of the present invention, are illus trated.

Figs. 1, 2 and 3 show in a vertical section, an end view and a side elevation respectively a first constructional example,

Figs. 4 and 5 show in a vertical section and in a side elevation respectively a second constructional example,

Figs. 6, 7 and 8 show a third constructional example in a vertical section, in an end view and in a section along line VIIIVIII in Fig. 6 respectively,

Figs. 9, 10, 11 and 12' show detail modifications,

Figs. 13 and let show in a vertical section and in an end view respectively a further constructional example,

Figs. 15 and 16 show details of the example illustrated in Figs. 13 and 14,

Fig. 17 serves for explaining a modification, of which Fig. 18 illustrates a detail on a larger scale.

In the first constructional example illustrated in Figs. 1-3, 1 denotes a mixing drum provided in its end walls 2 and 3 (held together by connecting bolts not illustrated in the accompanying drawings) with openings 4 and 5 respectively, of which the one 4 serves for filling in the material to be mixed below an inclined guide plate 6 and the other, 5, serves for discharging the material over a plate 7 when the mixing is completed. It will be noted that these plates are non-symmetrically arranged in the drum. The guide plate 6 is arranged in an obliqueguide 9 fixed to the frame 8 of the mixing machine, so that it may be displaced along the axial direction if desired, i. e. to project more or less into the interior of the drum. The guide plate 6 may be fixed in its adjusted positions in the guide 9, for instance, by means of a set screw or the like. Opposite the inclined guide plate 6 the guide plate 7 is turnable about axle pins 10 mounted in the frame 8, and a hand lever 11 is fixed on said axle pins 10 and serves for moving the guide plates 7 from the position shown in full lines into that shown in dotted lines. A spring loaded pin 12 permits the hand lever 11 to be locked to a sector 13 fixed to the frame 8 whereby the guide plate 7 is secured in its adjusted positions. The drum 1 is provided with a toothed rim 2" by means of which rotation is imparted to the mixing drum in a known manner.

During the mixing operation the guide plate 7 is in the position shown in full lines. The material to be mixed is lifted by the lifting blades 1% of the drum 1, and falls freely on the guide plates 6 and 7 and is deviated by these two plates in sucha manner that it flows over the guide plates partly in the transverse direction and partly in the longitudinal di- 9., rection of these plates, whereby the material to be mixed is 011 the one hand spread on the circumference of the drum and on the other hand is caused by the guide plates to form two streams which flow past each other. mo

When the guide plate 7 is in the position shown in dotted lines it deviates the material to be mixed in the same direction as the guide plate 6 whereby a quick discharge of the contents of the drum is obtained.

In the constructional example illustrated in Figs. 4 and 5 the guide plate 6 is turnable about a horizontal axle 15 and may be locked in the two positions illustrated by means of a. hand lever 16 and a spring loaded pin 17 cooperating with a sector 18. During the mixing the guide plate 6 is in the position shown in full lines. After the mixing is finished the guide plate 6 is turned into the position shown in dotted lines in which it is in the same plane as a chute 19 fixed to the frame 8, whereby the emptying of the drum is accelerated as the parts 6 and 19 assist the guide plate 7 in discharging the drum; in this case the guide plate 7 is adjusted in the position shown in dotted lines.

In the constructional example illustrated in Figs. 6, 7 and 8 the guide plate is turnable about a horizontal axle 100 and is adjustable in two inclined positions as has been described above. The guide plate 60 may be turned about an axle 21 by means of a hand lever 20 and may be locked in its adjusted positions by the aid of a spring loaded pin 22 cooperating with a sector 23. This con struetion permits an adjustment of the guide plate 60 with regard to its inclination to a vertical plane passing axially through the drum; the guide plate 70 is oppositely inclined to that vertical plane.

The above described arrangement of the two guide plates 60 and 70 as well as the adjustability of the plate 60 permit a regulation of the mixing.

In the modification illustrated in Fig. 9 both guide plates 61 and 71 are bent at the same longitudinal sides to form a guide edge 6' and 7' respectively which facilitates the currents of the material to be mixed to be guided past each other.

In the modification shown in Fig. 10 only the guide plate 61 is provided with a bent up portion forming a guide edge 6.

In the modification illustrated in Fig. 11 the guide plates 62 and 72 are slightly curved in cross-section so that concave guide faces for the material to be mixed are formed. The constructional example illustrated in Fig. 12 differs from that of Fig. 11 inasmuch as the guide plates 63 and 73 have an opposite curvature so that convex shaped guide surfaces cooperate with the material to be mixed.

In the constructional example illustrated in Figs. 13 and 14 the guide plate 64 is arranged stationary on the frame 8 while the guide plate 74 is turnable about an axle 10 which is arranged in plates 24 on wlnch a discharge channel 25 for the mixed material is mounted. The guide plate 7 4 may be secured in its position during the mixing operation by means of a latch 26 mounted on the frame 8. The guide plate 74 may be fixed in a similar manner in its second position during the emptying of the drum.

WVith each of the two guide plates 64 and 74 three lifting blades 27 and 28 respectively, which are equally spaced around the circumference of the drum cooperate. These blades extend from the respective end of the drum to beyond the middle plane of the drum so that the blades of each group project into the path of the blades of the other group. The blades 27 comprise a web plate A extending in the axial direction of the drum to which a bent longitudinal part B and a bent end part C join. The blades 28 have a supporting part D, a longitudinal part E and an end part F so that along the part E each blade is of an angular cross-section. shanks forming this angular cross-section of the blade 28 extends obliquely in the direction of the respective end wall of the drum (discharge side) in such a way that the blade tapers towards its other end and has thus a large opening F at the end corresponding to the discharge side of the drum and a smaller opening G at its other end. Figs. 15 and 16 show the blades 27 and 28 respectively, looking from above, in their lowermost position.

The lifting blades 27 and 28 are so staggered relatively to each other on the circumference of the drum 1, that when the drum rotates (in the direction of the arrow shown in Fig. 14) alternately one blade of the one group (27) and one blade of the other group (28) passes the lowermost position. The blades of both groups relieve each other in the lifting work. Of the material scooped by a single blade 27 during the upward movement of the latter a small portion falls over the longitudinal part B into the drum while another portion of the material falls over the end part C in order-to be partly or wholly caught by the next blade 28 of the second group. The blade 27 throws the bulk of the material transported by it on the guide plate 64 by which the greatest part of the material thus received is conveyed towards the opposite end of the drum while a small portion of that material falls into the drum along the longitudinal edges of the guide plate 64. The bulk of the material thereupon lifted by a blade 28 falls through the opening F onto the guide plate 74, a small portion of the material tumbles over the free longitudinal edge of the shank E and out of the smaller opening G into the drum. Of the material fed thus to the guide plate 74 a small portion falls along the longitudinal edges of this guide plate into the drum while the bulk of the material. on the guide plate 74 slides downward along the plate 74 towards the opposite end of the drum and gets thus into the path of the second group of blades and so on.

The apex of the two Thus a circulation of the material to be mixed inside the drum 18 obtained as is indicated by arrows and a dotted line connecting said arrows in Fig. 1. Thereby material to be mixed is periodically fed to the guide plates 64 and 74L whereby inside the drum streams of the material to be mixed moving in the axial direction are caused which owing to their not occurring simultaneously do not interfere with each other. Besides this positive deviation of the path of the material to be mixed from one end of the drum to the other a spreading of material on the circumference of the drum occurs, thus an intimate mixing is obtained in a minimum of time.

lVhen the guide plate 74 is adjusted into the position necessary for discharging the drum the circulation of the material present duripg the mixing operation is interrupted by the plate 74L, i. e. on its path indicated by transverse lines on the dotted line connecting up the arrows. Thereby a quick emptying of the drum results.

The modification illustrated in Figs, 17 and 18 differs from the constructional example described above only inasmuch as blades of the same kind are provided inside the drum, i. e. both groups of blades are formed by blades 28.

011 account of the continuous motion of the material inside the mixing drum, with all constructional examples the drum may be filled to a high degree whilst avoiding agglomerations of the material at the ends of the drum so that large openings in these ends may be provided to per iit a quick filling and emptying of the drum.

Obviously other modifications are possible and are included in the scope of the appended claims.

I claim:

1. A mixing drum for mixing concrete, mortar and the like, comprising in combina tion, blades fixed to the drum for lifting the materialto be mixed, and stationary inclined guide plates unsymmetrically arranged in opposition to each other whereby the material raised by said blades is caused to fall on said guide plates and to flow partly in the transverse direction and partly in the longitudinal direction off said plates in order to spread it in the circumferential direction and to be directed into axial streams flowing past each other.

2. A mixing drum for mixing concrete, mortar and the like, comprising in combination, blades fixed to the drum for lifting the material to be mixed, an inclined stationary guide plate on one end of the drum, and a turnable guide plate on the opposite end of the drum, said guide plates being so inclined that the mate 'ial raised by said blades is caused to fall on said guide plates and to flow partly in the transverse direction and partly in the longitudinal direction off said plates 1n order to spread it in the circumferential direction and to be directed into axial streams flowin in opposite directions past each other.

3. A mixing drum for mixing concrete, mortar and the like, comprising in combination, blades fixed to the drum for lifting the material to be mixed, and inclined guide plates so arranged opposite each other that the material raised by said blades is caused to fall on said guide plates and to flow partly in the transverse direction and partly in the longitudinal direction oif said plates in order to spread it in the circumferential direction and to be dir cted into axial streams flowing in opposite directions past each other, one of said plates having a bent up edge to form a guide edge for the respective stream.

4. A mixing drum for mixing concrete, motar and the like, comprising in combination, blades fixed to the drum for lifting the material to be mixed, inclined guide plates so arranged opposite each other that the material raised by said blades is caused to fall on said guide plates and to flow partly in the transverse direction and partly in the longitudinal direction oil said plates in order to spread it. in the circumferential direction and to be directed into axial streams flowing in opposite directions past each other, and means for adjusting the angle of inclination of both guide plates.

5. A mixing drum for mixing concrete, mortar and the like, comprising in combination, blades fixed to the drum for lifting the material to be mixed, an inclined stationary guide plate on one end of the drum, a turnable guide plate on the opposite end of the drum, said guide plates being so inclined that the material raised by said blades is caused to fall on said guide plates and to flow partly in the transverse-direction and partly in the longitudinal direction oil said plates in order to spread it in the circumferential direction and to be directed into axial streams flowing in opposite directions past each other, and a chute for emptying the drum, into the plane of which said turnable guide plate is adjusted when emptying the drum.

6. A mixing drum for mixing concrete, mortar and the like comprising in combina' tion, blad'es fixed to the drum for lifting the material to be mixed, and inclined guide plates so arranged opposite each other that the material raised by said blades is caused to fall on said guide plates and to flow partly in the transverse direction and partly in the longitudinal direction off said plates in order to spread it in the circumferential direction and to be directed into axial streams flowing in opposite directions past each other, said blades being so arranged relatively to said guide plates that material to be mixed is alternately fed to one and then to the other guide plate.

7 A mixing drum for mixing concrete,

motar and the like, comprising in combination, blades fixed to the drum for lifting the material to be mixed, and inclined guide plates so arranged opposite each other that the material raised by said blades is caused to fall on said guide plates and to flow partly in transverse direction and partly in the longitudinal direction off said plates in order to spread it in the circumferential direction and to be directed into axial streams flowing in opposite. directions past each other, said blades having angular cross-sections and tapering 'towards the respective end of the drum so that their discharge area at that end is smaller than at their other end.

8. A mixing drum for mixing concrete, mortar and the like, comprising in combination, blades fixed to the drum for lifting the material to be mixed, and inclined guide plates so arranged opposite each other that the material raised by said blades is caused to fall on said guide plates and to flow partly in the transverse direction and partly in the longitudinal direction off said plates in order to spread it in the circumferential direction and to be directed into axial streams flowing in opposite directions past each other, said blades mutually projecting into their paths of movement and being so arranged relatively to said guide plates that material to be mixed is alternately fed to one and then to the other guide plate.

9. A mixing machine having a horizontal drum having an opening at each end, two sets of blades therein, the blades of one set staggered with respect to the blades of the other, and an inclined plate projecting into the drum through each end opening onto which the blades alternately discharge.

10. A mixing machine comprising a horizontal drum having a central opening at each end, two sets of blades rigidly connected on the interior walls of the drum, the blades of one set staggered with respect to the blades of the other set, and a downwardly inclined plate projecting into each opening, at least one of the plates pivoted to swing upwardly.

In testimony whereof I have signed my name to this specification.

HEINRICH RUEF. 

